The daemon has made a habit of mutating the DefaultRuntime and Runtimes
values in the Config struct to merge defaults. This would be fine if it
was a part of the regular configuration loading and merging process,
as is done with other config options. The trouble is it does so in
surprising places, such as in functions with 'verify' or 'validate' in
their name. It has been necessary in order to validate that the user has
not defined a custom runtime named "runc" which would shadow the
built-in runtime of the same name. Other daemon code depends on the
runtime named "runc" always being defined in the config, but merging it
with the user config at the same time as the other defaults are merged
would trip the validation. The root of the issue is that the daemon has
used the same config values for both validating the daemon runtime
configuration as supplied by the user and for keeping track of which
runtimes have been set up by the daemon. Now that a completely separate
value is used for the latter purpose, surprising contortions are no
longer required to make the validation work as intended.
Consolidate the validation of the runtimes config and merging of the
built-in runtimes into the daemon.setupRuntimes() function. Set the
result of merging the built-in runtimes config and default default
runtime on the returned runtimes struct, without back-propagating it
onto the config.Config argument.
Signed-off-by: Cory Snider <csnider@mirantis.com>
The existing runtimes reload logic went to great lengths to replace the
directory containing runtime wrapper scripts as atomically as possible
within the limitations of the Linux filesystem ABI. Trouble is,
atomically swapping the wrapper scripts directory solves the wrong
problem! The runtime configuration is "locked in" when a container is
started, including the path to the runC binary. If a container is
started with a runtime which requires a daemon-managed wrapper script
and then the daemon is reloaded with a config which no longer requires
the wrapper script (i.e. some args -> no args, or the runtime is dropped
from the config), that container would become unmanageable. Any attempts
to stop, exec or otherwise perform lifecycle management operations on
the container are likely to fail due to the wrapper script no longer
existing at its original path.
Atomically swapping the wrapper scripts is also incompatible with the
read-copy-update paradigm for reloading configuration. A handler in the
daemon could retain a reference to the pre-reload configuration for an
indeterminate amount of time after the daemon configuration has been
reloaded and updated. It is possible for the daemon to attempt to start
a container using a deleted wrapper script if a request to run a
container races a reload.
Solve the problem of deleting referenced wrapper scripts by ensuring
that all wrapper scripts are *immutable* for the lifetime of the daemon
process. Any given runtime wrapper script must always exist with the
same contents, no matter how many times the daemon config is reloaded,
or what changes are made to the config. This is accomplished by using
everyone's favourite design pattern: content-addressable storage. Each
wrapper script file name is suffixed with the SHA-256 digest of its
contents to (probabilistically) guarantee immutability without needing
any concurrency control. Stale runtime wrapper scripts are only cleaned
up on the next daemon restart.
Split the derived runtimes configuration from the user-supplied
configuration to have a place to store derived state without mutating
the user-supplied configuration or exposing daemon internals in API
struct types. Hold the derived state and the user-supplied configuration
in a single struct value so that they can be updated as an atomic unit.
Signed-off-by: Cory Snider <csnider@mirantis.com>
Ensure data-race-free access to the daemon configuration without
locking by mutating a deep copy of the config and atomically storing
a pointer to the copy into the daemon-wide configStore value. Any
operations which need to read from the daemon config must capture the
configStore value only once and pass it around to guarantee a consistent
view of the config.
Signed-off-by: Cory Snider <csnider@mirantis.com>
Kubernetes only permits RuntimeClass values which are valid lowercase
RFC 1123 labels, which disallows the period character. This prevents
cri-dockerd from being able to support configuring alternative shimv2
runtimes for a pod as shimv2 runtime names must contain at least one
period character. Add support for configuring named shimv2 runtimes in
daemon.json so that runtime names can be aliased to
Kubernetes-compatible names.
Allow options to be set on shimv2 runtimes in daemon.json.
The names of the new daemon runtime config fields have been selected to
correspond with the equivalent field names in cri-containerd's
configuration so that users can more easily follow documentation from
the runtime vendor written for cri-containerd and apply it to
daemon.json.
Signed-off-by: Cory Snider <csnider@mirantis.com>
This type was added to support Solaris (which didn't support these
options). Solaris support was removed, so we can integrate this type
back into the "unix" type.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
This changes mounts.NewParser() to create a parser for the current operatingsystem,
instead of one specific to a (possibly non-matching, in case of LCOW) OS.
With the OS-specific handling being removed, the "OS" parameter is also removed
from `daemon.verifyContainerSettings()`, and various other container-related
functions.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
When a container is created if "--network" is set to "host" all the
ports in the container are bound to the host.
Thus, adding "-p" or "--publish" to the command-line is meaningless.
Unlike "docker run" and "docker create", "docker service create" sends
an error message when network mode is host and port bindings are given
This patch however suggests to send a warning message to the client when
such a case occurs.
The warning message is added to "warnings" which are returned from
"verifyPlatformContainerSettings".
Signed-off-by: Boaz Shuster <ripcurld.github@gmail.com>
